A systematic review and meta-analysis were conducted to estimate the prevalence of chlamydiosis in small ruminants. The study included 133 publications that reported the presence of Chlamydia abortus in 109 and 74 studies in sheep and goats from 45 countries. The prevalence of chlamydiosis was estimated at global, regional, and national levels using meta-analyses of proportions. Meta-regression and cumulative meta-analyses were also performed. Globally, the prevalence of chlamydiosis in sheep and goats was estimated at 20.1% (95% CI: 17.8-22.4) and 14.4% (11.6-17.4), respectively. For sheep, chlamydiosis prevalence was heterogeneous at regional and national levels. South Asia had the highest prevalence (30.6%) and East Asia and Pacific the lowest (14.0%). Nationally, chlamydiosis was more prevalent in Romania, Hungary, and Germany (range 53.3-87.0%) compared to Costa Rica, Australia, and Zimbabwe (4.7-5.2%). Among goats, chlamydiosis prevalence was similar across regions (10.4-19.7%), but varied significantly among countries, 0.0% in Romania and Australia and 91.7% in Bosnia and Herzegovina. In both species, sample size, number of diagnostic techniques, and latitude were significant covariates. Prevalence varied widely in the first decades of publications before stabilizing. Our study found a high prevalence of chlamydiosis in small ruminants, with the pathogen being distributed globally but heterogeneously across countries.

Contrary to pig farming in developed western countries, in a large part of the world, pigs are still traditionally kept, in small backyard farms, usually for family needs. Their main characteristics are low biosecurity, swill feeding, natural breeding and uncontrolled trade. Given the high number of backyard farms in Serbia and the risk they are thought to pose to intensive pig farming, the main aim of this study was to evaluate the prevalence of major viral diseases of swine among traditionally kept pigs in small holdings with low biosecurity. For this investigation, 222 serum samples from 69 backyard holdings were randomly selected and tested for PRRS, Aujeszky`s disease, PPV infection and Swine influenza by ELISA. The herd-level seroprevalence of PRRS, Aujeszky`s disease and PPV infection was 2.9%, 27.5% and 37.7%, respectively. Swine influenza seroconversion was not confirmed in any of the tested holdings. Despite widely distributed PPV and AD in backyard farms in Serbia, almost 50% of them are still negative for the all-tested disease. The backyard farms must be monitored, and owners educated as their role in eradication programs and obtaining country-free status may be crucial.